<title>Waveguide binary photonic true-time-delay lines using polymer integrated switches and waveguide delays</title>

Abstract

Photonic programmable binary delay lines capable of long total delay with small incremental intervals can greatly simplify delay line networks for phased array systems. With the increase in operation frequency and angular scan resolution, the delay length accuracy can reach magnitudes of micrometer for millimeter wave frequencies, while the largest delay length can be tens of centimeters for even a moderate number of array elements. Using micro-fabrication technologies, an integrated optic delay line/switch network can achieve such delay performance on a single integrated optic chip that is compact and light weight, and of low optical insertion loss. Polymer nonlinear optical materials have unique features that are particularly attractive to waveguide photonic integrated delay line applications. Long polymer waveguides can be fabricated on a large inexpensive wafer with microelectronics resolution, and integrated with fast electro-optic switches and broadband electro-optic modulators. With the advances in materials synthesis and device fabrication, such low cost polymer programmable delay line chips become increasingly realistic. We propose here an integrated polymer delay line design and report fabrication of polymeric photonic switches and modulators. The related technical issues, including material stability issues, that may affect device design, fabrication, and applications are also discussed.